Can Better Collaboration Between Dietitians and Psychologists Enhance Depression Treatment?

• Results of an online survey published in Translational Issues in Psychological Science examined some of the benefits and barriers to collaboration between dietitians and psychologists in depression treatment
• All participating clinicians agreed that there is a relationship between diet and depression
• 50% of psychologists and 30% of dietitians stated that patient care would improve if psychologists and nutritionists collaborated
• Career-specific jargon was the most frequently listed barrier to collaboration between these professions.

Although new mental health treatments are being developed every day, they are still not very effective. Large shares of individuals suffering from mental health issues do not respond to existing therapies or experience relapses not too long after remission (e.g., Bystritsky, 2006; McIntyre et al., 2023). This, at least partly, comes from the fact that mental health conditions are usually not caused by a single factor. They tend to have complex etiologies, and although many risk factors and changes associated with mental health disorders are well known, their causes are not fully understood.

Depression

One particularly common and serious mental health condition is depression. Depression is characterized by persistent sadness, hopelessness, and a loss of interest in activities once enjoyed. People with depression may experience persistent fatigue, sleep disturbances, appetite changes, difficulty concentrating, and feelings of worthlessness or guilt (see Figure 1).

Figure 1: Depression and its common symptoms

Unlike temporary sadness, depression persists for weeks, months, or even years. If left untreated, depression can increase the risk of self-harm or suicidal thoughts. Depressive patients have a 20-fold greater risk of suicide compared to the general population (Brådvik, 2018; Briley & Lépine, 2011).

Causes of depression are not fully understood, but it is clear that depression is a complex disorder with many different contributing factors (Bembnowska & Jośko-Ochojska, 2015). Conversely, treatments for depression are also not very effective. One estimate states that at least 30% of depressed individuals with access to high-quality care for depression will not respond to treatment and will be considered to suffer from treatment-resistant depression (McIntyre et al., 2023). When we take into account that not all people suffering from depression receive high-quality care, the share of successful treatments is even lower. McIntyre et al. (2023) estimate that only 5-7% of persons with depression treated in the primary care setting would be expected to achieve remission.

Only 5-7% of persons with depression treated in the primary care setting would be expected to achieve remission.

These are the reasons why researchers are on a constant lookout for ways to improve depression treatment. One relatively novel point of interest in this regard is diet.

Diet and depression

Recent decades have seen a large number of studies reporting links between depressive symptoms and eating patterns. For example, an analysis of the U.S. National Health and Nutrition Examination Survey (NHANES) database found that for every additional 100 grams of sugar intake per day, the odds of a person suffering from depression increase by 28% (Zhang et al., 2024). Similarly, the consumption of artificially sweetened beverages was found to be associated with an increased risk of depression (Hedrih, 2023; Samuthpongtorn et al., 2023).

For every additional 100 grams of sugar intake per day, the odds of a person suffering from depression increase by 28%.

Studies reported that individuals with higher dietary fiber intake are less likely to suffer from depression or to contemplate suicide (a symptom common in severe depression) (Fatahi et al., 2021; Huang et al., 2024). And there are many more.

The current study

Study authors Colette F. H. Stenz and Kate L. Jansen wanted to investigate psychologists’ and dietitians’ views on the benefits and barriers to their collaboration in treating depressive patients. They recruited 32 psychologists and 34 dietitians through a professional organization in Arizona to complete an online survey.

The survey asked about participants’ views on the relationship between diet and depression (e.g., “I believe there is a relationship between diet and depression”) and about how much they discuss the relationship between diet and depression with clients (and if they feel confident in those discussions). It also contained two questions examining participants’ knowledge about the nutrition-depression relationship.

Next, the survey presented three case vignettes – one depicting a clinical psychologist giving suggestions about diet change to a client with depression, one about a dietitian in a similar situation, and one about a collaboration between a psychologist and a dietitian.

Participants reported whether such discussions were in the depicted clinician’s scope of practice, if the clinician should have referred the patient to someone else, and if the clinician in the vignette could give credible advice. The survey ended with open-ended questions about barriers and benefits to collaboration between dietitians and psychologists, and some more questions about participants’ educational background and whether they made referrals for diet or mood (see Figure 2).

Figure 2. Study protocol (Stenz and Jansen, 2023)

 

Clinicians agree that there is a bidirectional relationship between diet and depression

Results showed that all participating clinicians agreed there is a bidirectional relationship between diet and depression. Dietitians and psychologists demonstrated similar levels of knowledge on the topic of the diet-depression relationship and displayed similar levels of confidence in discussing this topic with patients. 63% of psychologists believed that it is within their scope of practice to discuss diet with patients, but this was the case with only 12% of dietitians. 50% of psychologists, but only 3% of dietitians, believed that psychologists could give credible advice about diet.

84% of psychologists reported asking depressed patients about their diet, and a similar percentage referred them to dietitians, nutritionists, and physicians for this. Only 47% of dietitians indicated asking their clients about mood or mental health (see Figure 3).

Figure 3. Clinicians’ Perspectives on the Diet-Depression Relationship

 

Psychologists and dietitians agree that care for depressed patients would improve if their professions collaborated

All psychologists and almost all dietitians believed that patient care would improve if their professions collaborated. Improved and more appropriate care was listed as the main benefit (50% of psychologists, 30% of dietitians). Career-specific jargon was listed as the main barrier to collaboration between these professions (16% of psychologists, 15% of dietitians), followed by differences in client communications, issues related to the scope of practice, and trust between professions (see Figure 4).

Figure 4. Beliefs and barriers

Conclusion

Overall, psychologists and dietitians participating in this survey believed that there is a bidirectional relationship between depression and diet. Psychologists generally believed that depressed patients’ diet was within their scope of practice and that they could give credible advice on the topic, but dietitians did not share this view about psychologists’ competencies. Both professions agreed that patient care would improve if their professions collaborated, but they saw career-specific jargon as the main barrier to collaboration.

Overall, the study showed that both of the studied professions recognize diet as a pathway to helping individuals with depression. This might indicate that the results of novel studies on the relationship between diet and mental health are being applied in practice at least to some extent.

The 2023 paper “Nutrition and Depression: Collaboration Between Psychologists and Dietitians in Depression Treatment” was authored by Colette F. H. Stenz and Kate L. Jansen.

More studies on the collaboration between nutrition and psychology can be found in the Nutritional Psychology Research Library (NPRL) Towards Interdisciplinary Efforts research category.

References

Bembnowska, M., & Jośko-Ochojska, J. (2015). What causes depression in adults? Polish Journal of Public Health, 125(2), 116–120. https://doi.org/10.1515/pjph-2015-0037

Brådvik, L. (2018). Suicide Risk and Mental Disorders. International Journal of Environmental Research and Public Health, 15(9), 2028. https://doi.org/10.3390/ijerph15092028

Briley, M. & Lépine. (2011). The increasing burden of depression. Neuropsychiatric Disease and Treatment, 3. https://doi.org/10.2147/NDT.S19617

Bystritsky, A. (2006). Treatment-resistant anxiety disorders. Molecular Psychiatry, 11(9), 805–814. https://doi.org/10.1038/sj.mp.4001852

Fatahi, S., Matin, S. S., Sohouli, M. H., Găman, M.-A., Raee, P., Olang, B., Kathirgamathamby, V., Santos, H. O., Guimarães, N. S., & Shidfar, F. (2021). Association of dietary fiber and depression symptom: A systematic review and meta-analysis of observational studies. Complementary Therapies in Medicine, 56, 102621. https://doi.org/10.1016/j.ctim.2020.102621

Hedrih, V. (2023). Women Consuming Lots of Artificially Sweetened Beverages Might Have a Higher Risk of Depression, Study Finds. CNP Articles in Nutritional Psychology. https://www.nutritional-psychology.org/women-consuming-lots-of-artificially-sweetened-beverages-might-have-a-higher-risk-of-depression-study-finds/

Huang, H., Fu, J., Lu, K., Fu, Y., Zhuge, P., & Yao, Y. (2024). Association between dietary fiber intake and suicidal ideation: A cross-sectional survey. Frontiers in Nutrition, 11, 1465736. https://doi.org/10.3389/fnut.2024.1465736

McIntyre, R. S., Alsuwaidan, M., Baune, B. T., Berk, M., Demyttenaere, K., Goldberg, J. F., Gorwood, P., Ho, R., Kasper, S., Kennedy, S. H., Ly-Uson, J., Mansur, R. B., McAllister-Williams, R. H., Murrough, J. W., Nemeroff, C. B., Nierenberg, A. A., Rosenblat, J. D., Sanacora, G., Schatzberg, A. F., … Maj, M. (2023). Treatment-resistant depression: Definition, prevalence, detection, management, and investigational interventions. World Psychiatry, 22(3), 394–412. https://doi.org/10.1002/wps.21120

Samuthpongtorn, C., Nguyen, L. H., Okereke, O. I., Wang, D. D., Song, M., Chan, A. T., & Mehta, R. S. (2023). Consumption of Ultraprocessed Food and Risk of Depression. JAMA Network Open, 6(9), e2334770. https://doi.org/10.1001/jamanetworkopen.2023.34770

Zhang, L., Sun, H., Liu, Z., Yang, J., & Liu, Y. (2024). Association between dietary sugar intake and depression in US adults: A cross-sectional study using data from the National Health and Nutrition Examination Survey 2011–2018. BMC Psychiatry, 24(110), 1–10. https://doi.org/10.1186/s12888-024-05531-7